Method of producing cellulose articles



r. neon, or cirrcaco, rumors,

Parser OFFER 210], OF CHICAGO, ILLINOIS, A. CORPORATION OF VIRGINIA.

amrnon or rsonuomc cnnm 1 {0 as; ABE! f."

Application fllcfl November 1980. fierial flo. 498,487.

The invention relates to apparatus for producing articles from celluloseand more an ticularly to apparatus for producing cell ose tubes orsausage c s.

In the preferred em odiment of the invention, the cellulose tub ispreferably formed from viscose which is obtained by practicing themethod briefly described in U. S. Letters Patent No. 1,612,508, granted1% December 28 1926, to William F. Henderson and Harold Dietrich. Theviscose is extruded through an annular orifice and is subjected to oneor more solutions so that it again becomes cellulose or cellulosehydrate.

e tubing is then washed in water and sub-' sequently treated with ahygroscopic agent, such as glycerine, to prevent it from drying to suchan extent that it willcrack.

e present invention relates particularly to improved apparatus for andan improved method of was in the tubing after it has been ersed in t ehardening solutions.

In practicing the improved method, the tubing is washed in a series ofwash tanks holding warm water at difierent temperatures, the arrangementbein such that the tubing is thoroughly close of the byproducts resultinfrom the reaction oi the viscose and the her ening baths or solutions.The temperature of the water in the several tanks is sucn that the usesevolved do not accumulate more rapidl than they can difiuse through thecellu ose wall and, erefore, there is no excessive overstre I: ct tubingand it is not deformed Other objects and advantages of the inve tionwill become apparent as the following detailed description progresses,reference being had to the accompan drawing, wherein:

Figure 1 is a somewhat diagratic V ew of a section taken throughapparatus which embodies the invention.

Fig. 2 is an enlarged fragmentary section taken through one of a purality of wash t shown in Fig. 1, and

Fig. 3 is a die am of electrical apparatus which is utilize to controlthe temperature of the water in the wash tanks.

the.

apparatus for extruding viscose through an annular orifice to formcellulose tubing which is shown at 11, the tubing being exanon. remvrsxmc comm-- traded into a coagulating or regenerating hath 13 andbeing advanced over aroller 14" to a tank 15 holdin a coagulating orregenerating solution. rom the receptacle 15 the tubing is advanced to areceptacle 16 which holds an aqueous solution of the coagulating orregeneratin agents, these agents being carried over mto the solutionfrom the receptacle "15 b the tubing. lhe tubing is then advanced romthe receptacle 16 through a plurality of wash tanks 17, 18, 19 and 20,and thence into a receptacle 21 which holds a hygroscopic agent,preferably glycerine. lldler rolls 23 in the receptacles 15, 16,17, 1819, 20 and 21 and driven rolls 24 disposed a ove these receptacles guideand advance, respectively, the tubing through the several receptacles.

Various solutions are employed in the eutruding apparatus and in therece tacle 15 for hardening the viscose. In practicing one embodiment ofthe invention an aqueous solution of 8 to 10% of sulfuric cold and 12 to16% of sodium-sulfate is employed in the dium'sulfate is employed in theextrug apparatus, the extruding apparatus being provided with areceptacle 25 which holds 1 these solutions. In the event the secondsolution is employed in the receptacle 15, a regenerating solution isemployed in the rece tacle 15.

e reaction of the acidified salt baths and, the viscose produces severalsubstances, such as sodium sulfate, sodium bisulfate, hy-

drogen sulfide, colloidal sulfur, etc., all of which must be washed outof the regenerated cellulose film before it is dried.

this purpose that the tubing is conveyed through the wash tanks 17, 18,19 and 20, which tanks preferably hold running water. 10

It isfor '8 leaving the acidified is associated with t Hot water willremove these biroducts from the film or tube much more quic y than coldwater. However, if the film or tube is carried into hot waterimmediately after regenerating bath an result. The acid which eregenerated film soon lmparts a permanent acidity to the water in thefirst wash tank if the water is not changed often enough to prevent suchacidity. If the temperature is high, this acid exerts a weakening effecton the cellulose film. Volatile substances formed by the action of theacid on the viscose are quickly driven out of the film when it isimmersed in hot water, and, under certain conditions, may cause minuteas bubbles to be formed in the film itself. ese volatile substances areprobabl hydrogen sulfide, carbon disulfide and car on dioxide. Theproduction of these volatile biproducts resents the greatest difficultywhen the ce ulose product is in the form of a seamless tube. Here, asubstantial rise in temperature following the regenerate or cellulosewhen the tube is lead into hot water causes an inflation of the tube bythe gases trapped inside. Under these conditions, the gases accumulatemore rapidly than they can diffuse through the cellulose wall andserious overstretching and deformation results.

Regenerated cellulose films are subject to severe shrinkage during theregenerating operation and during subsequent washing stages, and the useof hot water accelerates this shrinkage. The application of hot waterimmediately after the acid treatment causes such severe and suddenshrinkage that frequent breakage may occur.

The present invention permits the use of hot water for washing theregenerated cellulose films or tubes without encountering thedifliculties mentioned above. Thus, the temperature of the water in thewash tanks 17, 18, 19 and 20 is adually raised, beginning with water ata ut the same temperature as that maintained in the acid tank and endingin the final wash tank 20 with hot water. In a preferred embodiment ofthe invention, the water in tank 17 is held at approximately 20 0., thewater in the second tank .18 is held at about 30 C., the water in thetank 19 is held at about 35 C., and the water in the tank 20 is held at50 0., or even higher.

As indicated above, the water in the tanks 17, 18, 19, and 20 ispreferably; changed at frequent intervals or continuous thus pipes 17a,18a,19a and 20a are adapted to discharge water into the receptacles 1718, 19 and 20, respectively, the overflow being carried off by pipes17b, 18b, 19b and 206, respectively. If it is so desired, each of thetanks 17, 18, 19 and 20 may be connected to a larger tank so that thewater may becirculated continuously. Such construction permits theteminferior product ma perature of the water to be readily controlled.

In the preferred embodiment of the invention, means is preferablyassociated with each of the tanks 17 18, 19 and 20 to control thetemperature of the water therein. In this instance, the controllingmeans comprises heating devices 30, 31, 32 and 33 disposed in the tanks17, 18, 19 and 20, respectively, the heating devices being preferablyelectrical resistances. The resistances are connected to a suitablesource (not shown) of electrical energy, as illustrated in Fig. 3. Theresistances 30, 31, 32 and 33 are controlled by thermostatic devices 35,36, 37 and 38, respectively, which are preferably identical inconstruction. The thermostatic device 35 is illustrated in detail inFig. 2 and comprises, in this instance, a diaphra 39 holding a quantityof some suitable v0 atile fluid which will expand when it is heated. Thediaphragm is carried by a bracket 40 mounted in the tank 17 thediaphragm being positiqfipd beneath the surface of the water in the ta vThe free end of the diaphragm 39 is connected by a post 41 to a lever 42which is pivoted intermediate its ends to a bracket 43 carried by thetank 17. A member 44, depending from one end of the lever 42, is adaptedto depress a metallic spring member 45 when the diaphragm 39 expands.The spring member 45 carries a contact point 46 engageable with acontact point 47 carried by a spring member 48. The spring members 45and 48 are insulated from each other and are mounted in a housing 49secured to a wall of the tank 17. A set screw 50 screw-threaded throughone of the walls of the housing 49 engages the spring member 48 and isadapted to bring it into a plurality of adjusted positions. Thus, thespring member 48 tends to flex in an upward direction and the screw 50may be manipulated against this action to bring the contact point 47into any desired position with respect to the contact point 46. Thespring mem er 45 also tends to. spring upward so as to bring the contactpoint 46 into engagement with the contact point 47. Obviously, theapparatus may be adjusted in such manner that the circuit through the resistance 30 may be closed unless the water in the tank 17 is at least 200., or any other temperature that may be desired.

The thermostatic devices 36, 37, and 38 are adjusted to maintain thetemperatures noted above in the tanks 18, 19 and 20, respectively, orany other temperatures that may be desired.

Briefiy,in the operation of the above described ap aratus, the tubing 11passes from the extru ing mechanism 10 through the tanks 15 and 16 intothe first wash tank 17 and thence through the wash tanks 18, 19 and y inthe tanks 17, 1'8, 19 and 20 is contrenee gt;

' the thermostatic devices 35, 36, 37 and respectively, in the mannerdescribedabove so that the casing or tubing is not sub'ected 5 to a hightemperature immediately a r it reaches the tank 16, but is graduallysubjected to hi her temperatures until it has een thoroug 1y washed.

While I have shown and described certain 19 embodiments of my invention,it is to be 'un- V ders'tood that it is capable of many modifications.Changes, therefore, in the construction and arrangement may be madewithout departing from the spirit and scope of the invention asdisclosed in the appended claims,

in which it is my intention to claim all novel ty inherent in aninvention as broadly as possible, in view 0 the prior art.

' I claim:

20 1. The method of forming a cellulose product, which method comprisesextruding viscose and regenerating it and subjecting the regeneratedviscose to several baths of heated water of increasing temperature.

2. The method of forming a cellulose prodnot, which method comprisesextruding viscose, regenerating it, and washing the regeneratedsubstance in several baths of heated water of increasing temperatures,one of said baths beilag maintained at a temperautre less than 409 andanother of said baths be' gairgained .at a temperature in excess 0 3.The method of forming a cellulose prodnot, which method comprisesextruding viscose, regeneratingsaid viscose, and washing the regeneratedsubstance in at least three baths of heated water of increasingtemperatures, at least one of said baths being main- 40 tained at atemperature in excess of 35 C.

In testimony whereof, I hereuntov afliz; mysignature this 24th day ofOctober, 1930.

wILLmM r. ENDERSON.

